1. Field of the Invention
The present invention relates to a panel, and in particular to a metallic key panel assembly.
2. Description of Prior Art
With the continuous progress of communication technologies, many electronic products are manufactured to a more compact extent so as to reduce the size and weight of the electronic product. Thus, it is convenient for a user to carry about such a compact electronic product. In order to reduce the size and weight of the electronic product, not only the volume of the internal integrated circuit is reduced, but also the area and thickness of a keyboard on an operating interface of the electronic product should be reduced. As a result, the electronic product can be mounted on a communication device easily.
As shown in FIGS. 1(a) and 1(b), US Patent Publication No. 2007/0205986A1 discloses a conventional metallic panel 10a having an elastic layer 1a. One side surface of the elastic layer 1a has thereon a plurality of protrusions 11a. The other side surface of the elastic layer 1a is arranged with a plurality of metallic keys 2a to correspond to the protrusions 11a. The metallic key 2a has a hollowed portion 21a with a corresponding pattern. A light transmittable resin layer 22a is filled in the hollowed portion 21a. When the metallic key panel 10a is disposed in a base 20a of an electronic device, the metallic key panel 10a is located on a telecommunication module 30a. The telecommunication module 30a has a printed circuit board 31a. The circuit board 31a has a plurality of immovable contacting points 32a. A metallic sheet 33a is disposed on the circuit board 31a. The metallic sheet 33a has thereon a plurality of convex metal domes 331a. The metal dome 331a corresponds to each contacting point 32a, and the other side surface of the metal sheet 331a corresponds to the protrusion 11a. When the metallic key 2a is pressed, the protrusion 11a is caused to press the surface of the metal dome 331a, so that the metal dome 331a is deformed and brought into contact with the contacting point 32a, thereby generating an electronic signal output. Further, when a backlight source is lighted up, the light of the backlight source can pass through the resin layer 22a of the metallic key 2a, so that the user can see the position of each key clearly.
Although the above-mentioned metallic key panel 10a has been manufactured to a more compact extent and can be mounted in a small-volume electronic device, during the manufacturing process, it is necessary to fill the individual hollowed portions 21a on the metallic key 2a with the resin layer 22a, and each of the metallic keys 2a has to be adhered onto one side surface of the elastic layer la accurately. As a result, the manufacturing process takes a lot of time and labors and is not simple. After the metallic key panel 10a is combined with the base 20a, a gap is formed between the periphery of the metallic key 2a and the base 20a, and the gap may be filled by external dusts or penetrated by moisture easily. As a result, the metallic key cannot be pressed smoothly or an internal short circuit may occur. Further, when the backlight source of the metallic panel 10a is lighted up, the hollowed portion 21a of the key 2a merely displays single luster. Therefore, the external appearance and the overall visual effect of the metallic key panel are dull.